Titanium-based composite part and preparation method and application thereof

Abstract

The invention belongs to the technical field of powder metallurgy, and particularly relates to a titanium-based composite workpiece and a preparation method and application thereof. High-entropy alloy powder with fine granularity is preferably selected as reinforcing phase powder after being prepared by adopting a gas atomization method and subjected to vibration screening, the particle size of the reinforcing phase powder and internal crystal grains of particles are fine, and after the reinforcing phase powder and titanium alloy powder are uniformly mixed, hot isostatic pressing low-temperature sintering treatment is performed, so that the high-entropy titanium alloy is obtained. Fine grain structures in reinforced phase powder particles are reserved in the titanium-based composite master alloy bar, and then a secondary plasma rotating electrode method is used for preparing powder, so that the titanium-based composite powder with uniform components and smaller grain structures is obtained; after mixing, the homogenized titanium-based composite mother alloy bar is prepared into powder through a secondary plasma rotating electrode method, chemical components are further dispersed and homogenized, reinforcing phases are distributed in all titanium-based composite powder particles, and the reinforcing effect can be further improved through an unconventional surface contact type reinforcing mode.

Description

Technical Field

[0001] The invention belongs to the technical field of powder metallurgy, and in particular relates to a titanium-based composite product and a preparation method and application thereof. Background Art

[0002] Particle-reinforced titanium-based composites, usually with carbides, nitrides, oxide ceramic particles and whiskers as reinforcements, can greatly improve the strength, hardness, wear resistance and creep resistance of titanium-based composites. Therefore, titanium-based composites have been widely used in key components such as aircraft engine turbine blades and high-pressure compressor discs, and have gradually become one of the irreplaceable key strategic materials in major national equipment fields such as aerospace. The composite design concept of particle-reinforced titanium-based composites pursues uniform dispersion of reinforcements in the matrix. By optimizing the type, morphology and content ratio of reinforcements, the reinforcements play a pinning and bearing role on the grain boundary, so that the material can obtain uniform and stable performance. However, the strengthening effect of the homogenization design concept has certain limitations: that is, the improvement of material strength and heat resistance temperature is often at the expense of plasticity. With the increase of the volume fraction of reinforcements, the reinforcements will inevitably coarsen and agglomerate, thereby inducing stress concentration and introducing defects, which seriously affects the plasticity of the material. This makes particle-reinforced titanium-based composites unable to break through the bottleneck of "strength-plasticity inversion". In addition, since the uniformity of particle distribution in the matrix is ​​difficult to control, when the ceramic reinforcement particles are unevenly distributed or even seriously aggregated, an arch bridge effect will be formed, resulting in uneven organization. When the aggregated reinforcement phase in the titanium-based composite material and the titanium matrix resist external forces unevenly, stress concentration will occur and the material's ability to resist plastic deformation will be weakened.

[0003] As a new type of alloy material, high entropy alloy usually has excellent mechanical properties, corrosion resistance, thermal stability and high temperature oxidation resistance, and has gradually become a research hotspot in the field of materials. Therefore, by introducing high entropy alloy particles into titanium-based composites, the hardness and strength of titanium-based composites can be effectively improved, while maintaining or improving the plasticity of titanium-based composites. Therefore, the preparation of titanium-based composites with uniformly dispersed reinforced particles is of great significance for improving the comprehensive mechanical properties of materials.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a titanium-based composite part and a preparation method and application thereof.

[0006] To achieve the above object, the present invention provides the following technical solutions: In one aspect, the present invention provides a method for preparing a titanium-based composite material, comprising the following steps: Step 1: preparing a high entropy alloy powder with a particle size of 10 to 50 μm by gas atomization and airflow screening or vibration screening in a high-purity argon atmosphere; The parameters for preparing high entropy alloy powder by the gas atomization method are as follows: the diameter of the master alloy rod of the high entropy alloy powder is 50 mm to 80 mm, the length is 100 mm to 600 mm, the powder making power efficiency is 50% to 80%, the feed speed is 50 mm / min to 100 mm / min, and the gas flow rate during the airflow screening is 600 Nm 3 / h~1200Nm 3 / h; Step 2: preparing titanium alloy powder with a particle size of 10 μm to 150 μm by using a plasma rotating electrode method and vibrating and sieving in a high-purity argon atmosphere; The parameters for preparing titanium alloy powder by the plasma rotating electrode method are as follows: the diameter of the master alloy rod of the titanium alloy powder is 50 mm to 80 mm, the rotation speed is 20000 r / min to 32000 r / min, the feed speed is 20 mm / min to 50 mm / min, the arc distance is 30 mm to 50 mm, the current is 1000 A to 1400 A, the voltage is 80 V to 90 V, and the vacuum degree is less than 5×10 -3 Pa; Step 3, mixing the high entropy alloy powder and the titanium alloy powder in a double cone mixer according to a specific ratio to obtain a titanium-based mixed powder with a particle size of 10 μm to 150 μm; wherein the mass fraction of the high entropy alloy powder in the titanium-based mixed powder is 0.1% to 8.0%; the parameters of the double cone mixer during mixing are: a rotation speed of 10 r / min to 30 r / min, and a mixing time of 60 min to 180 min; Step 4, firstly loading the titanium-based mixed powder into a first steel ladle, then sequentially subjecting the first steel ladle to mechanical compaction, vacuum degassing, and micro-beam plasma sealing and welding treatments, and then subjecting the first steel ladle to hot isostatic pressing, and then mechanically removing the first steel ladle after furnace cooling to obtain a titanium-based composite master alloy rod, wherein the titanium-based composite master alloy rod has a diameter of 50 mm to 80 mm and a length of 500 mm to 700 mm; Step 5: Powder the titanium-based composite master alloy rod by a plasma rotating electrode method and vibrate screen to obtain a titanium-based composite powder with a particle size of 10 μm to 150 μm; wherein the parameters for preparing the titanium-based composite powder by the plasma rotating electrode method are as follows: the rotation speed of the titanium-based composite master alloy rod is 20000 r / min to 32000 r / min, the feed speed is 20 mm / min to 50 mm / min, the arc distance is 30 mm to 50 mm, the current is 1000 A to 1400 A, the voltage is 80 V to 90 V, and the vacuum degree is less than 5×10 -3 Pa; Step 6: firstly load the titanium-based composite powder into a second steel ladle, then sequentially perform mechanical vibration, vacuum degassing, micro-beam plasma sealing welding on the second steel ladle, and then perform hot isostatic pressing, and after cooling in the furnace, mechanically remove the second steel ladle to finally obtain the desired titanium-based composite part.

[0007] Specifically, in step 2, the titanium alloy powder is one of α-type titanium alloy, α+β-type titanium alloy and β-type titanium alloy; preferably, the α-type titanium alloy is selected from TA series titanium alloys, such as one of Ti-5Al-2.5Sn and Ti-6.5Al-1Mo-1V-2Zr; the α+β-type titanium alloy is selected from TC series titanium alloys, such as one of Ti-6Al-4V, Ti-6Al-2Sn-4Zr-2Mo and Ti-6.5Al-2Zr-1Mo-1V; the β-type titanium alloy is selected from TB series titanium alloys, such as one of Ti-10V-2Fe-3Al and Ti-15V-3Cr-3Sn-3Al.

[0008] Specifically, the high entropy alloy powder includes one of AlCoCrFeNi, AlCrCoNiCu, CuCrFeTiNi, CoCrMoNbTi, and FeCoNiTaAl.

[0009] Specifically, in step 2 and step 4, the degassing process is divided into two steps: the first step is to heat the temperature to 300°C~400°C, the heating rate is 2°C / min~10°C / min, and degas to a vacuum degree of ≤1.0×10 -3 Pa; the second step is to heat up to 400℃~500℃, the heating rate is 2℃ / min~5℃ / min, and degas to a vacuum degree of ≤1.0×10 -4 Pa.

[0010] Specifically, in step 2 and step 4, the parameters of the micro-beam plasma sealing welding are: welding current is 10A~20A, arc voltage is 15V~30V, and welding speed is 0.5mm / s~2.5mm / s; Specifically, in step 4 and step 6, the parameters of the hot isostatic pressing are: temperature of 850°C to 950°C, heating rate of 2°C / min to 20°C / min, pressure of 100MPa to 150MPa, and holding time of 120min to 180min; the materials of the first ladle jacket and the second ladle jacket are both 20 steel.

[0011] It should be noted that there is no strict order between step 1 and step 2 in the preparation method of the present invention, and the order is subject to actual production.

[0012] On the other hand, the present invention provides a titanium-based composite product, which is prepared by the preparation method described above.

[0013] On the other hand, the present invention provides an application of a titanium-based composite product, which is used in aircraft engine turbine blades and high-pressure compressor disks.

[0014] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: The invention adopts a gas atomization method to prepare a high-entropy alloy powder with fine grains after vibration screening as the reinforcing phase powder. The particle size of the reinforcing phase powder and the grains inside the particles are fine. After being evenly mixed with the titanium alloy powder, the powder is subjected to hot isostatic pressing and low-temperature sintering treatment, so that the fine grain structure inside the reinforcing phase powder particles can be retained in the titanium-based composite master alloy rod. Then, the secondary plasma rotating electrode method is used to prepare the powder to obtain a titanium-based composite powder with uniform composition and finer grain size. The titanium-based composite powder is formed by hot isostatic pressing, and the forming temperature is controlled at a level lower than 950°C, thereby avoiding the traditional hot pressing sintering. The titanium-based composite master alloy rods that have been homogenized after mixing are powdered by the secondary plasma rotating electrode method, and the chemical composition is further dispersed and homogenized, and the reinforcing phase is distributed inside each titanium-based composite powder particle. The unconventional surface contact strengthening method can further improve the strengthening effect; and the titanium-based composite powder particles prepared by the secondary method retain the characteristics of density, high sphericity, good fluidity, etc. of the plasma rotating electrode method powder preparation, which is suitable for effective filling of various shapes of packages, and has a higher tap density, which is conducive to further hot isostatic pressing densification molding. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the present invention.

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0017] Figure 1 is a flow chart of the preparation method of the present invention; Figure 2 This is a scanning electron microscope image of the titanium-based composite powder prepared in Example 1 of the present invention; Figure 3 This is a microstructure diagram of the titanium-based composite product A prepared in Example 1 of the present invention; Figure 4This is a scanning electron microscope image of the titanium-based composite powder prepared in Example 2 of the present invention; Figure 5 This is a microstructure diagram of the titanium-based composite product B prepared in Example 2 of the present invention; Figure 6 This is a scanning electron microscope image of the titanium-based composite powder prepared in Example 3 of the present invention; Figure 7 This is a microstructure diagram of the titanium-based composite product C prepared in Example 3 of the present invention. DETAILED DESCRIPTION

[0018] Here, exemplary embodiments will be described in detail, and examples thereof are shown in the accompanying drawings. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples consistent with some aspects of the present invention as detailed in the appended claims.

[0019] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0020] The present invention provides a method for preparing a titanium-based composite part, comprising the following steps: Step 1, preparing by gas atomization method and using air flow screening or vibration screening in a high-purity argon atmosphere to obtain a high entropy alloy powder with a particle size of 10 μm to 50 μm; The parameters for preparing high entropy alloy powder by the gas atomization method are as follows: the diameter of the master alloy rod of the high entropy alloy powder is 50 mm to 80 mm, the length is 100 mm to 600 mm, the powder making power efficiency is 50% to 80%, the feed speed is 50 mm / min to 100 mm / min, and the gas flow rate during the airflow screening is 600 Nm 3 / h~1200Nm 3 / h; Step 2: preparing titanium alloy powder with a particle size of 10 μm to 150 μm by using a plasma rotating electrode method and vibrating and sieving in a high-purity argon atmosphere; The parameters for preparing titanium alloy powder by the plasma rotating electrode method are as follows: the diameter of the master alloy rod of the titanium alloy powder is 50 mm to 80 mm, the rotation speed is 20000 r / min to 32000 r / min, the feed speed is 20 mm / min to 50 mm / min, the arc distance is 30 mm to 50 mm, the current is 1000 A to 1400 A, the voltage is 80 V to 90 V, and the vacuum degree is less than 5×10 -3 Pa; Step 3, mixing the high entropy alloy powder and the titanium alloy powder in a double cone mixer according to a specific ratio to obtain a titanium-based mixed powder with a particle size of 10 μm to 150 μm; wherein the mass fraction of the high entropy alloy powder in the titanium-based mixed powder is 0.1% to 8.0%; the parameters of the double cone mixer during mixing are: a rotation speed of 10 r / min to 30 r / min, and a mixing time of 60 min to 180 min; Step 4, firstly loading the titanium-based mixed powder into a first steel ladle, then sequentially subjecting the first steel ladle to mechanical compaction, vacuum degassing, and micro-beam plasma sealing and welding treatments, and then subjecting the first steel ladle to hot isostatic pressing, and then mechanically removing the first steel ladle after furnace cooling to obtain a titanium-based composite master alloy rod, wherein the titanium-based composite master alloy rod has a diameter of 50 mm to 80 mm and a length of 500 mm to 700 mm; Step 5: Powder the titanium-based composite master alloy rod by a plasma rotating electrode method and vibrate screen to obtain a titanium-based composite powder with a particle size of 10 μm to 150 μm; wherein the parameters for preparing the titanium-based composite powder by the plasma rotating electrode method are as follows: the rotation speed of the titanium-based composite master alloy rod is 20000 r / min to 32000 r / min, the feed speed is 20 mm / min to 50 mm / min, the arc distance is 30 mm to 50 mm, the current is 1000 A to 1400 A, the voltage is 80 V to 90 V, and the vacuum degree is less than 5×10 - 3 Pa; Step 6: firstly load the titanium-based composite powder into a second steel ladle, then sequentially perform mechanical vibration, vacuum degassing, micro-beam plasma sealing welding on the second steel ladle, and then perform hot isostatic pressing, and after cooling in the furnace, mechanically remove the second steel ladle to finally obtain the desired titanium-based composite part.

[0021] Specifically, in step 2, the titanium alloy powder is one of α-type titanium alloy, α+β-type titanium alloy and β-type titanium alloy; preferably, the α-type titanium alloy is selected from TA series titanium alloys, such as one of Ti-5Al-2.5Sn and Ti-6.5Al-1Mo-1V-2Zr; the α+β-type titanium alloy is selected from TC series titanium alloys, such as one of Ti-6Al-4V, Ti-6Al-2Sn-4Zr-2Mo and Ti-6.5Al-2Zr-1Mo-1V; the β-type titanium alloy is selected from TB series titanium alloys, such as one of Ti-10V-2Fe-3Al and Ti-15V-3Cr-3Sn-3Al.

[0022] Specifically, the high entropy alloy powder includes one of AlCoCrFeNi, AlCrCoNiCu, CuCrFeTiNi, CoCrMoNbTi, and FeCoNiTaAl.

[0023] Specifically, in step 2 and step 4, the degassing process is divided into two steps: the first step is to heat the temperature to 300°C~400°C, the heating rate is 2°C / min~10°C / min, and degas to a vacuum degree of ≤1.0×10 -3 Pa; the second step is to heat up to 400℃~500℃, the heating rate is 2℃ / min~5℃ / min, and degas to a vacuum degree of ≤1.0×10 -4 Pa.

[0024] Specifically, in step 2 and step 4, the parameters of the micro-beam plasma sealing welding are: welding current is 10A~20A, arc voltage is 15V~30V, and welding speed is 0.5mm / s~2.5mm / s; Specifically, in step 4 and step 6, the parameters of the hot isostatic pressing are: temperature of 850°C to 950°C, heating rate of 2°C / min to 20°C / min, pressure of 100MPa to 150MPa, and holding time of 120min to 180min; the materials of the first ladle jacket and the second ladle jacket are both 20 steel.

[0025] In order to prove the effect of the preparation method of the present invention, the following examples are provided for verification. Example 1

[0026] This embodiment provides a method for preparing a titanium-based composite component. Figure 1 As shown, the specific steps are as follows: Step 1: Atomize the AlCoCrFeNi master alloy rod to obtain AlCoCrFeNi powder with a particle size of 10 μm to 50 μm after airflow screening; wherein the diameter of the AlCoCrFeNi master alloy rod is 50 mm, the length is 600 mm, the power efficiency during powder preparation is 60%, the feed speed is 70 mm / min, and the gas flow rate during airflow screening is 1000 Nm 3 / h; Step 2: Prepare by plasma rotating electrode method and screen by rotary vibrating screen under argon protection to obtain TC4 (Ti-6Al-4V) alloy powder with a particle size of 10 μm to 150 μm; The parameters for preparing TC4 alloy powder by the plasma rotating electrode method are as follows: the diameter of the TC4 master alloy rod is 50 mm, the length is 700 mm, the rotation speed is 32000 r / min, the feed value is 25 mm / min, the distance between the TC4 master alloy rod and the plasma arc (PV value) is 35 mm, the current is 1200 A, and the voltage is 80 V; in addition, before powdering, three TC4 master alloy rods are used to wash the furnace to consume the residual gas components in the atomization chamber; the purity of the argon gas is 99.999%; Step 3: Mix the TC4 alloy powder and the AlCoCrFeNi powder in a double cone mixer to obtain a titanium-based mixed powder with a particle size of 10 μm to 150 μm; wherein the introduction ratio of the AlCoCrFeNi powder is 0.2 wt.%, the rotation speed of the double cone mixer is 30 r / min, and the mixing time is 120 min; see Figure 2 As shown, Figure 2 This is a scanning electron microscope image of the titanium-based mixed powder, with the AlCoCrFeNi powder highlighted in the image; Step 4: First, the titanium-based mixed powder is loaded into a first steel ladle made of 20 steel, and after mechanical vibration, it is degassed at 400°C to 8.9×10 -4 Pa, and then degassed at 500℃ to 8.3×10 -5 After the quenching, micro plasma sealing welding is adopted, and then the temperature is kept at 850℃ and the pressure is 150MPa for 180min, and then the first steel ladle is removed by machining after cooling to room temperature, so as to obtain titanium-based composite master alloy rods; Step 5: Powder the titanium-based composite master alloy rod by a plasma rotating electrode method, and after vibration screening, obtain a titanium-based composite powder with a particle size of 10 μm to 150 μm; the parameters for preparing the titanium-based composite powder by the plasma rotating electrode method are as follows: the rotation speed of the titanium-based composite master alloy rod is 20000 r / min, the feed speed is 50 mm / min, the arc distance is 30 mm, the current is 1400 A, the voltage is 80 V, and the vacuum degree is <5×10 -3 Pa; Step 6: First, the titanium-based composite powder is loaded into a second steel ladle made of 20 steel, and after mechanical vibration, it is degassed at 400°C to 8.9×10 -4 Pa, and then degassed at 500℃ to 8.3×10 -5 After Pa, micro-beam plasma sealing welding is adopted, and then the temperature is kept at 850℃ and the pressure is 150MPa for 180min, and then the second steel jacket is removed by machining after cooling to room temperature with the furnace, and finally the titanium-based composite part A is obtained; Specifically, in step 4 and step 6, the parameters of the micro-beam plasma sealing welding are: welding current is 20A, arc voltage is 15V, and welding speed is 2.5mm / s.

[0027] The microstructure of the prepared titanium-based composite part A was observed. Figure 3 As shown, it can be seen that high entropy alloy particles, as the second phase, precipitate at the grain boundaries. The precipitated phase can effectively hinder the movement of dislocations, that is, when the titanium alloy matrix is ​​subjected to stress, the high entropy alloy particles pin the dislocations to make the deformation more uniform; the presence of high entropy alloy particles introduces a strain gradient, promotes multi-system slip of dislocations, improves the uniform deformation capacity of the workpiece, and thus delays fracture. Example 2

[0028] This embodiment provides a method for preparing a titanium-based composite component. Figure 1 As shown, the specific steps are as follows: Step 1, atomizing the AlCrCoNiCu master alloy rod to obtain AlCrCoNiCu powder with a particle size of 10μm~50μm after airflow screening; wherein the diameter of the AlCrCoNiCu master alloy rod is 60mm, the length is 600mm, the power efficiency during powder making is 50%, the feed speed is 50mm / min, and the gas flow rate during airflow screening is 900Nm 3 / h; Step 2: Prepare by plasma rotating electrode method and screen by rotary vibrating screen under argon protection to obtain TA15 (Ti-6.5Al-1Mo-1V-2Zr) alloy powder with a particle size of 10 μm to 150 μm; The parameters for preparing TA15 alloy powder by the plasma rotating electrode method are as follows: the diameter of the TA15 master alloy rod is 60 mm, the length is 700 mm, the rotation speed is 25000 r / min, the feed value is 30 mm / min, the distance (PV value) between the TA15 master alloy rod and the plasma arc is 35 mm, the current is 1300 A, and the voltage is 82 V; in addition, before powdering, three TA15 master alloy rods are used for furnace washing to consume the residual gas components in the atomization chamber; the purity of the argon gas is 99.999%; Step 3: Mix the TA15 alloy powder and the AlCrCoNiCu powder in a double cone mixer to obtain a titanium-based mixed powder with a particle size of 10 μm to 150 μm; wherein the introduction ratio of the AlCrCoNiCu powder is 1.0 wt.%, the rotation speed of the double cone mixer is 30 r / min, and the mixing time is 80 min; see Figure 4 As shown, Figure 4 This is a scanning electron microscope image of the titanium-based mixed powder, with the highlighted part being the AlCrCoNiCu powder; Step 4: First, the titanium-based mixed powder is loaded into a first steel ladle made of 20 steel, and after mechanical vibration, it is degassed at 400°C to 5.3×10 -4 Pa, and then degassed at 500℃ to 9.2×10 -5 After Pa, micro-beam plasma sealing welding is adopted, and then the temperature is kept at 880℃ and the pressure is 130MPa for 150min, and then the first steel ladle is removed by machining after cooling to room temperature with the furnace to obtain a titanium-based composite master alloy rod; Step 5: Powder the titanium-based composite master alloy rod by a plasma rotating electrode method, and obtain a titanium-based composite powder with a particle size of 10 μm to 150 μm after vibration screening; the parameters of the plasma rotating electrode method for preparing the titanium-based composite powder are as follows: the rotation speed of the titanium-based composite master alloy rod is 25000 r / min, the feed speed is 35 mm / min, the arc distance is 40 mm, the current is 1200 A, the voltage is 85 V, and the vacuum degree is less than 5×10 -3 Pa; Step 6: First, the titanium-based composite powder is loaded into a second steel ladle made of 20 steel, and after mechanical vibration, it is degassed at 400°C to 5.3×10 -4 Pa, and then degassed at 500℃ to 9.2×10 -5 After Pa, micro-beam plasma sealing welding is adopted, and then the temperature is kept at 880℃ and pressure of 130MPa for 150min, and then the second steel jacket is removed by machining after cooling to room temperature with the furnace, and finally the titanium-based composite part B is obtained; Specifically, in step 4 and step 6, the parameters of the micro-beam plasma sealing welding are: welding current is 15A, arc voltage is 22V, and welding speed is 1.5mm / s.

[0029] The microstructure of the prepared titanium-based composite part B was observed. Figure 5 As shown, it can be seen that high entropy alloy particles, as the second phase, precipitate at the grain boundaries. The precipitated phase can effectively hinder the movement of dislocations, that is, when the titanium alloy matrix is ​​subjected to stress, the high entropy alloy particles pin the dislocations to make the deformation more uniform; the presence of high entropy alloy particles introduces a strain gradient, promotes multi-system slip of dislocations, improves the uniform deformation capacity of the workpiece, and thus delays fracture. Example 3

[0030] This embodiment provides a method for preparing a titanium-based composite component. Figure 1 As shown, the specific steps are as follows: Step 1, atomizing the AlCoCrFeNi master alloy rod to obtain AlCoCrFeNi powder with a particle size of 10 μm to 50 μm after vibration screening; wherein the diameter of the AlCoCrFeNi master alloy rod is 80 mm, the length is 400 mm, the power efficiency during powder making is 80%, and the feed speed is 90 mm / min; Step 2: Prepare by plasma rotating electrode method and obtain TB6 (Ti-10V-2Fe-3Al) alloy powder with a particle size of 10 μm to 150 μm by vibration screening under argon protection; The parameters for preparing TB6 alloy powder by the plasma rotating electrode method are as follows: the diameter of the TB6 master alloy rod is 80 mm, the length is 700 mm, the rotation speed is 20000 r / min, the feed value is 45 mm / min, the distance between the TB6 master alloy rod and the plasma arc (PV value) is 45 mm, the current is 1000 A, and the voltage is 88 V; in addition, before powdering, three TB6 master alloy rods are used for furnace washing to consume the residual gas components in the atomization chamber; the purity of the argon gas is 99.999%; Step 3: Mix the TB6 alloy powder and the AlCoCrFeNi powder in a double cone mixer to obtain a titanium-based mixed powder with a particle size of 10 μm to 150 μm; wherein the introduction ratio of the AlCoCrFeNi powder is 7.0 wt.%, the speed of the double cone mixer is 15 r / min, and the mixing time is 180 min; see Figure 6 As shown, Figure 6 This is a scanning electron microscope image of the titanium-based mixed powder, with the AlCoCrFeNi powder highlighted in the image; Step 4: First, the titanium-based mixed powder is loaded into a first steel ladle made of 20 steel, mechanically vibrated, and degassed at 300°C to 6.5×10 -4 Pa, and then degassed at 400℃ to 7.5×10 -5 After the reaction was completed, micro plasma sealing was performed, and then the mixture was kept at 950°C and 100 MPa for 120 min, and then the first steel jacket was removed by machining after being cooled to room temperature, thereby obtaining a titanium-based composite master alloy rod. Step 5: Powder the titanium-based composite master alloy rod by a plasma rotating electrode method, and after vibration screening, obtain a titanium-based composite powder with a particle size of 10 μm to 150 μm; the parameters for preparing the titanium-based composite powder by the plasma rotating electrode method are as follows: the rotation speed of the titanium-based composite master alloy rod is 32000 r / min, the feed speed is 20 mm / min, the arc distance is 50 mm, the current is 1000 A, the voltage is 90 V, and the vacuum degree is <5×10 -3 Pa; Step 6: First, the titanium-based composite powder is loaded into a second steel ladle made of 20 steel, mechanically vibrated, and degassed at 300°C to 6.5×10 -4 Pa, and then degassed at 400℃ to 7.5×10 -5 After Pa, micro-beam plasma sealing welding is adopted, and then the temperature is kept at 950℃ and pressure of 100MPa for 120min, and then the second steel jacket is removed by machining after cooling to room temperature with the furnace, and finally the titanium-based composite part C is obtained; Specifically, in step 4 and step 6, the parameters of the micro-beam plasma sealing welding are: welding current is 10A, arc voltage is 30V, and welding speed is 0.5mm / s.

[0031] The microstructure of the prepared titanium-based composite part C was observed. Figure 7 As shown, it can be seen that high entropy alloy particles, as the second phase, precipitate at the grain boundaries. The precipitated phase can effectively hinder the movement of dislocations, that is, when the titanium alloy matrix is ​​subjected to stress, the high entropy alloy particles pin the dislocations to make the deformation more uniform; the presence of high entropy alloy particles introduces a strain gradient, promotes multi-system slip of dislocations, improves the uniform deformation capacity of the workpiece, and thus delays fracture.

[0032] In order to verify the mechanical properties of the titanium-based composite parts A, B and C prepared in the embodiments of the present invention, a tensile test was carried out at room temperature. The test results are shown in Table 1: Table 1 Tensile strength MPa Yield strength MPa Elongation% Sectional shrinkage% Example 1 980 875 19 45 Example 2 1050 950 15 43 Example 3 1180 1010 12 42 As shown in Table 1, the titanium-based composite parts prepared by the preparation method of the present invention have a tensile strength of ≥980 MPa, a yield strength of ≥875 MPa, an elongation of ≥15%, and a cross-sectional shrinkage of >40% after tensile testing, and have good strength and plasticity, meeting the actual use requirements of aircraft engine turbine blades and high-pressure compressor disks.

[0033] It should also be noted that the titanium-based composite parts prepared by the preparation method of the present invention, compared with traditional titanium-based composite parts, significantly increase the lattice distortion due to the introduction of high entropy alloys, and the high entropy alloy particles themselves as the second phase can effectively hinder the movement of dislocations, that is, when the titanium alloy matrix is ​​subjected to stress, the high entropy alloy particles play a certain pinning effect on the dislocations, and the increase of precipitated phases on the grain boundaries will also hinder the movement of dislocations. Its interface effect also makes the stress distribution more uniform, reduces stress concentration, and delays crack propagation, which will further improve the yield strength and tensile strength of the composite parts. In addition, when the introduction of high entropy alloy particles is mixed with multiple elements in nearly equal proportions on a microscopic scale, it is usually easy to form simple crystal configurations such as face-centered cubic (FCC) or body-centered cubic (BCC), and at the same time, it will be accompanied by trace metal intermetallic compounds or multiphase structures such as amorphous phases. This multiphase structure can cooperate with deformation, so that the parts show higher plasticity on a macroscopic scale. As a second phase, high entropy alloy particles can effectively hinder the expansion of cracks. That is, when cracks encounter high entropy alloy particles during the expansion process, they need to consume more energy to continue to expand. When dislocations bypass or cut around high entropy alloy particles, they will cause more dislocation proliferation and interaction, making the deformation more uniform. Furthermore, the presence of high entropy alloy particles introduces strain gradients, promotes multi-system slip of dislocations, improves the uniform deformation ability of the workpiece, and thus delays fracture. Furthermore, the interface bonding strength between high entropy alloy particles and titanium alloy matrix is ​​high, which can effectively transfer stress, avoid local stress concentration, make the stress distribution near the interface more uniform, and delay local plastic instability.

[0034] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0035] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for preparing a titanium-based composite part, characterized in that: The steps include: Step 1: preparing high entropy alloy powder of a specific particle size by gas atomization; Step 2: preparing titanium alloy powder of a specific particle size by using a plasma rotating electrode method; Step 3, mixing the high entropy alloy powder and the titanium alloy powder in a specific ratio to obtain a titanium-based mixed powder; Step 4, firstly put the titanium-based mixed powder into a first package, then perform vibration compaction, degassing, sealing and welding treatments on the first package in sequence, and then perform hot isostatic pressing, and remove the first package after cooling to obtain a titanium-based composite master alloy rod; Step 5: Powdering the titanium-based composite master alloy rod by a plasma rotating electrode method to obtain a titanium-based composite powder of a specific particle size; Step 6: first put the titanium-based composite powder into a second package, then perform vibration compaction, degassing, and sealing treatments on the second package in sequence, and then perform hot isostatic pressing. After cooling, remove the second package to finally obtain the desired titanium-based composite product.

2. The method for preparing a titanium-based composite part according to claim 1, characterized in that: In step 1, the parameters for preparing high entropy alloy powder by the gas atomization method are: power efficiency of 50% to 80%, and feed speed of 50 mm / min to 100 mm / min.

3. The method for preparing a titanium-based composite component according to claim 1, characterized in that: In step 2, the parameters for preparing titanium alloy powder by the plasma rotating electrode method are: rotation speed of 20000r / min~32000r / min, feed speed of 20mm / min~50mm / min, arc distance of 30mm~50mm, current of 1000A~1400A, voltage of 80V~90V, vacuum degree of <5×10 - 3 Pa.

4. The method for preparing a titanium-based composite part according to claim 1, characterized in that: In step 2, the titanium alloy powder is one of α-type titanium alloy, α+β-type titanium alloy and β-type titanium alloy.

5. The method for preparing a titanium-based composite part according to claim 1, characterized in that: In step 3, the mass fraction of the high entropy alloy powder in the titanium-based mixed powder is 0.1% to 8.0%.

6. The method for preparing a titanium-based composite part according to claim 1, characterized in that: The high entropy alloy powder is one of AlCoCrFeNi, AlCrCoNiCu, CuCrFeTiNi, CoCrMoNbTi, and FeCoNiTaAl.

7. The method for preparing a titanium-based composite part according to claim 1, characterized in that: In step 4 and step 6, the degassing process is a two-step process: the first step is to heat the temperature to 300°C to 400°C and degas to a vacuum degree of ≤1.0×10 -3 Pa; the second step is to heat up to 400℃~500℃ and degas to a vacuum degree of ≤1.0×10 -4 Pa.

8. The method for preparing a titanium-based composite part according to claim 1, characterized in that: In step 4 and step 6, the parameters of the hot isostatic pressing are: temperature of 850°C to 950°C, heating rate of 2°C / min to 20°C / min, pressure of 100MPa to 150MPa, and holding time of 120min to 180min.

9. A titanium-based composite part, characterized in that: The method is described in any one of claims 1 to 8.

10. The use of the titanium-based composite product according to claim 9, characterized in that: Application in aircraft engine turbine blades and high-pressure compressor discs.

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